Method of refining oil.



GEORGE M. HOLBROOK, OF CHICAGO, ILLINOIS, ASSIGNOR T0 ARMOUR AND COMPANY,

' OF CHICAGO, ILLINOIS, A. CORPORATION OF ILLINOIS.

METHOD OF REFINING OIL.

No Drawing.

To all whom it may concern Be it known that I, GEORGE M. HOLBROOK, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Methods of Refining Oil, of which the following is a specification.

My invention pertains to methods of refining or purifying oil, such for example, as crude cotton-seed oil, and one of the salient features of the invention resides in the provision of a process of this kind which will produce a clarified oil of desired color with a minimum loss or shrinkage in performing the process.

To effect this result it is desirable to use a silicate, such as sodium or potassium sili cate, to bring about a condensing or compacting of the soap-stock or foots produced, but this chemical is so employed that it will not have an injurious effect on the decolorizing or clarifying of the oil.

It has been suggested, as for example in United States Patent No. 1,007 ,642, granted October 31, 1911, that the acidity of the crude cotton-seed oil may be first approximately overcome or neutralized by an alkaline silicate, such for example, as by means of an aqueous solution of a water-soluble alkaline silicate, more specifically and preferably sodium tetrasilicate, and then the oil may be subjected to the action of sodium hydroxid efiecting a precipitation of the soap-stock from which the refined oil is separated.

Experience has indicated that a process of this kind is objectionable because the initial use of the silicate appears to so set or fix the coloring matter in the oil that it is difficult or impossible by subsequent treatment to produce the proper clarifying efiect at least without the employment of an excessive amount of sodium hydroxid and a consequent increase in the shrinkage or refining loss, the latter depending largely upon the amount of sodium hydroxid used.

I have found that in order to produce the best results both as to color and shrinkage or refining loss, the proposed use of such silicate for the purpose of neutralizing the fatty acids must be avoided, and, accordingly, I have invented a newand different process by which the desired end may be secured.

Specification of Letters Patent.

paratively minor amount and in the pres ence of such an overwhelming quantity of hydroxid, that the deleteriouskefiect of the.

silicate on the coloring matterlis prevented; or, stated in other words, the free fatty acids are completely neutralized or so nearly overcome by the sodium hydroxid before the sodium silicate has an opportunity to act that the injurious effect upon the color referred to does not take place.

In performing this process, the percentages of ingredients or temperatures employed, etc., will be varied to conform to the characteristics of the crude cotton-seed oil treated, andwill depend to some extent upon the color required and the permissible loss in shrinkage. As a typical case,-however, I might mention that with crude cotton-seed oil containing free; fatty acids of 1%, there would be added to the oil a mixture composed offour per cent. (4%) by weight of the oil treated of an aqueous solution of sodium hydroxid, 18 Baum, or its equivalent in caustic strength, .and three fourths 1-) of one per cent. (1%) by weight of the oil of an aqueous solution of sodium silicateof commercial grade, 71. e. 44: Baum, the mixture being agitated for approxi- Patented Jan. 25, 1916.

Application filed November 15, 1915. Serial No. 61,502. '7

mately 15 minutes and 'its temperature gradually raised from about 80 Fahrenheit to about 115 Fahrenheit, at which point the soap-stock will readily and completely separate from the refined -oil, the

latter being much clearer and of lighter described in connection .with t'e refining and purifying of cotton-seed oil, it is to be understood that 1 its use is not limited and restricted to any particular kind of oil, but is adapted for employment in connection with manyvegetable and animal oils.

Iclaim: v

1. The process of refining crude cottonseed 'oiland the like, consisting in subjecting thev oil to a mixture of an aqueous solution of caustic alkali and an aqueous solution of a silicate in such proportions that the caustic alkali'neutralizes either wholly or in part the free fatty acids of the oil before the silicate can set or fix the coloring matter of the oil, and separating the refined oil from the soap-stock produced, substantially asdescribed. 2. The process of refining crude cottonseed oil and the like, consisting in subjecting the crude oil to a mixture of an aqueous solution of sodium hydroxid and an aqueous solution of sodium silicate in such proportions that the 'hydroxid neutralizes the free fatty acids either wholly or in part before the silicate can have a setting or fixing effect on the coloring matter, and separat ing the refined oil from the soap-stock produced, substantially as described.

3. The process of refining crude cottonseed oil and the like, consisting in adding to the crude oil a mixture of an aqueous solution of caustic alkali and, an aqueous solution of a silicate in such proportions that the caustic alkali neutralizes the free fatty acids of the oil either wholly or in .part before the silicate sets. or fixesthe color, agitating the mixture and gradually I 7 raising its temperature,

and separating'the refined oil from the soap-stock produced, substantially as described.

4. The process of refining crude cottonseet oil and the like containing approxi mately. one (1%) per cent. of free fatty acids, consisting in adding to the oil to be treated a mixture comprosed of'approximately four (4%) per cent. by weight ofthe oil under treatment of an aqueous solution of sodium hydroxid, 18' Baum and approximately three-fourths of one (1%) per cent. by weight of the oil to be. treated of an aqueous solution of sodium silicate, 44 Baum, agitating the mixture and gradually raising its temperature until the soap-stock settles, and then separating the refined oil 56 from the soap-stock produced,'substantially as described. L Y

- GEORGE M. HOLBRQOK. 

